The development of email is one of the most significant advances of the computer age. (The United States Postal Service is often referred to as snail mail now)
With a few keystrokes and a click of your mouse, you can send messages that are delivered within seconds (depending on how well your mail server and the Internet are working), and you can receive a reply within a matter of minutes.
You can have Outlook sort your email by the name of the sender, the date the message was received, or a number of other elements. No matter how you want to digest or process information, Outlook can present it to you in a way that's ready to use. Just think of how much time that can save you.